Upgrading and Fixing Computers: Do-it-Yourself For Dummies®

Chapter 16. Filtering Out Evil with Firewalls

Tasks in this chapter

• Turning on (or off) Windows 7 Firewall

• Allowing or stopping a program from poking through Windows 7 Firewall

• Manually changing Windows 7 Firewall settings

Even if you're not using a traditional network in your home or office, you're exposed to a network nearly every day. The Internet is a vast network connecting computers around the world. And those connections come with dangers.

See, your computer opens a door to the Internet whenever it asks for information. And naturally, because your computer needs to receive information — a Web page, for example — the computer holds that door open.

Unfortunately, some people make a habit of looking for open doors and trying to sneak in when nobody's looking. Why? For some people, the childish thrill of seeing if they can snoop around in Jeff's locker without getting caught is just too tempting to resist.

Others sneak in like burglars, looking for credit card numbers, e-mail addresses, or other private files. Still others are vandals, destroying whatever they get their hands on. The business-minded crooks quietly take over computers, and then sell them to spammers, who surreptitiously crank out junk mail, all unnoticed by the computer's owner.

Simply put, your computer needs somebody to stand guard at the door, opening and closing the door at the right times to filter out the bad folks.

A firewall is that security guard, and this chapter explains how to turn on Windows 7's built-in firewall, ...